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package com.sun.imageio.plugins.tiff;

import javax.imageio.plugins.tiff.BaselineTIFFTagSet;
import javax.imageio.plugins.tiff.TIFFField;
import javax.imageio.plugins.tiff.TIFFTag;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Iterator;
import javax.imageio.ImageReader;
import javax.imageio.ImageWriteParam;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.spi.IIORegistry;
import javax.imageio.spi.ImageReaderSpi;
import javax.imageio.spi.ServiceRegistry;
import javax.imageio.stream.MemoryCacheImageInputStream;
import javax.imageio.stream.MemoryCacheImageOutputStream;

Compressor for encoding compression type 7, TTN2/Adobe JPEG-in-TIFF.
/** * Compressor for encoding compression type 7, TTN2/Adobe JPEG-in-TIFF. */
public class TIFFJPEGCompressor extends TIFFBaseJPEGCompressor { // Subsampling factor for chroma bands (Cb Cr). static final int CHROMA_SUBSAMPLING = 2;
A filter which identifies the ImageReaderSpi of a JPEG reader which supports JPEG native stream metadata.
/** * A filter which identifies the ImageReaderSpi of a JPEG reader * which supports JPEG native stream metadata. */
private static class JPEGSPIFilter implements ServiceRegistry.Filter { JPEGSPIFilter() {} public boolean filter(Object provider) { ImageReaderSpi readerSPI = (ImageReaderSpi)provider; if(readerSPI != null) { String streamMetadataName = readerSPI.getNativeStreamMetadataFormatName(); if(streamMetadataName != null) { return streamMetadataName.equals(STREAM_METADATA_NAME); } else { return false; } } return false; } }
Retrieves a JPEG reader which supports native JPEG stream metadata.
/** * Retrieves a JPEG reader which supports native JPEG stream metadata. */
private static ImageReader getJPEGTablesReader() { ImageReader jpegReader = null; try { IIORegistry registry = IIORegistry.getDefaultInstance(); Iterator<?> readerSPIs = registry.getServiceProviders(ImageReaderSpi.class, new JPEGSPIFilter(), true); if(readerSPIs.hasNext()) { ImageReaderSpi jpegReaderSPI = (ImageReaderSpi)readerSPIs.next(); jpegReader = jpegReaderSPI.createReaderInstance(); } } catch(Exception e) { // Ignore it ... } return jpegReader; } public TIFFJPEGCompressor(ImageWriteParam param) { super("JPEG", BaselineTIFFTagSet.COMPRESSION_JPEG, false, param); }
Sets the value of the metadata field.

The implementation in this class also adds the TIFF fields JPEGTables, YCbCrSubSampling, YCbCrPositioning, and ReferenceBlackWhite superseding any prior settings of those fields.

Params:
  • metadata – the IIOMetadata object for the image being written.
See Also:
/** * Sets the value of the {@code metadata} field. * * <p>The implementation in this class also adds the TIFF fields * JPEGTables, YCbCrSubSampling, YCbCrPositioning, and * ReferenceBlackWhite superseding any prior settings of those * fields.</p> * * @param metadata the {@code IIOMetadata} object for the * image being written. * * @see #getMetadata() */
public void setMetadata(IIOMetadata metadata) { super.setMetadata(metadata); if (metadata instanceof TIFFImageMetadata) { TIFFImageMetadata tim = (TIFFImageMetadata)metadata; TIFFIFD rootIFD = tim.getRootIFD(); BaselineTIFFTagSet base = BaselineTIFFTagSet.getInstance(); TIFFField f = tim.getTIFFField(BaselineTIFFTagSet.TAG_SAMPLES_PER_PIXEL); int numBands = f.getAsInt(0); if(numBands == 1) { // Remove YCbCr fields not relevant for grayscale. rootIFD.removeTIFFField(BaselineTIFFTagSet.TAG_Y_CB_CR_SUBSAMPLING); rootIFD.removeTIFFField(BaselineTIFFTagSet.TAG_Y_CB_CR_POSITIONING); rootIFD.removeTIFFField(BaselineTIFFTagSet.TAG_REFERENCE_BLACK_WHITE); } else { // numBands == 3 // Replace YCbCr fields. // YCbCrSubSampling TIFFField YCbCrSubSamplingField = new TIFFField (base.getTag(BaselineTIFFTagSet.TAG_Y_CB_CR_SUBSAMPLING), TIFFTag.TIFF_SHORT, 2, new char[] {CHROMA_SUBSAMPLING, CHROMA_SUBSAMPLING}); rootIFD.addTIFFField(YCbCrSubSamplingField); // YCbCrPositioning TIFFField YCbCrPositioningField = new TIFFField (base.getTag(BaselineTIFFTagSet.TAG_Y_CB_CR_POSITIONING), TIFFTag.TIFF_SHORT, 1, new char[] {BaselineTIFFTagSet.Y_CB_CR_POSITIONING_CENTERED}); rootIFD.addTIFFField(YCbCrPositioningField); // ReferenceBlackWhite TIFFField referenceBlackWhiteField = new TIFFField (base.getTag(BaselineTIFFTagSet.TAG_REFERENCE_BLACK_WHITE), TIFFTag.TIFF_RATIONAL, 6, new long[][] { // no headroon/footroom {0, 1}, {255, 1}, {128, 1}, {255, 1}, {128, 1}, {255, 1} }); rootIFD.addTIFFField(referenceBlackWhiteField); } // JPEGTables field is written if and only if one is // already present in the metadata. If one is present // and has either zero length or does not represent a // valid tables-only stream, then a JPEGTables field // will be written initialized to the standard tables- // only stream written by the JPEG writer. // Retrieve the JPEGTables field. TIFFField JPEGTablesField = tim.getTIFFField(BaselineTIFFTagSet.TAG_JPEG_TABLES); // Initialize JPEG writer to one supporting abbreviated streams. if(JPEGTablesField != null) { // Intialize the JPEG writer to one that supports stream // metadata, i.e., abbreviated streams, and may or may not // support image metadata. initJPEGWriter(true, false); } // Write JPEGTables field if a writer supporting abbreviated // streams was available. if(JPEGTablesField != null && JPEGWriter != null) { // Set the abbreviated stream flag. this.writeAbbreviatedStream = true; //Branch based on field value count. if(JPEGTablesField.getCount() > 0) { // Derive the stream metadata from the field. // Get the field values. byte[] tables = JPEGTablesField.getAsBytes(); // Create an input stream for the tables. ByteArrayInputStream bais = new ByteArrayInputStream(tables); MemoryCacheImageInputStream iis = new MemoryCacheImageInputStream(bais); // Read the tables stream using the JPEG reader. ImageReader jpegReader = getJPEGTablesReader(); jpegReader.setInput(iis); // Initialize the stream metadata object. try { JPEGStreamMetadata = jpegReader.getStreamMetadata(); } catch(Exception e) { // Fall back to default tables. JPEGStreamMetadata = null; } finally { jpegReader.reset(); } } if(JPEGStreamMetadata == null) { // Derive the field from default stream metadata. // Get default stream metadata. JPEGStreamMetadata = JPEGWriter.getDefaultStreamMetadata(JPEGParam); // Create an output stream for the tables. ByteArrayOutputStream tableByteStream = new ByteArrayOutputStream(); MemoryCacheImageOutputStream tableStream = new MemoryCacheImageOutputStream(tableByteStream); // Write a tables-only stream. JPEGWriter.setOutput(tableStream); try { JPEGWriter.prepareWriteSequence(JPEGStreamMetadata); tableStream.flush(); JPEGWriter.endWriteSequence(); // Get the tables-only stream content. byte[] tables = tableByteStream.toByteArray(); // Add the JPEGTables field. JPEGTablesField = new TIFFField (base.getTag(BaselineTIFFTagSet.TAG_JPEG_TABLES), TIFFTag.TIFF_UNDEFINED, tables.length, tables); rootIFD.addTIFFField(JPEGTablesField); } catch(Exception e) { // Do not write JPEGTables field. rootIFD.removeTIFFField(BaselineTIFFTagSet.TAG_JPEG_TABLES); this.writeAbbreviatedStream = false; } } } else { // Do not write JPEGTables field. // Remove any field present. rootIFD.removeTIFFField(BaselineTIFFTagSet.TAG_JPEG_TABLES); // Initialize the writer preferring codecLib. initJPEGWriter(false, false); } } } }